At the time of Griffith's Valuation William Longfield's estate was in the parishes of Athleague and Fuerty, barony of Athlone, the parish of Kilnamanagh, barony of Frenchpark and the parish of Kiltullagh, barony of Castlereagh, county Roscommon. Rocksavage was owned by the Lysters and held by William Longfield under a fee farm grant dated 30 Jan 1851. Rocksavage was part of the Lyster estate offered for sale in the Encumbered Estates' Court in 1855. By the 1870s various members of the Longfield family, mostly with addresses in Dublin, held almost 4000 acres in county Roscommon, including Robert Longfield of Dublin who owned 2,448 acres. The estate of W. D. Longfield and others amounting to 3,728 acres was vested in the Congested Districts' Board on 15 June 1907.
|Name||Townland||Civil Parish||PLU||DED||Barony||County||Map Ref|
|Rocksavage||Knockadangan||Athleague||Roscommon||Athleague West 74||Athlone||Roscommon||
OSI Ref: M862 591
OS Sheet: 41
Discovery map: 40
OSI Ref: M713944
OS Sheet: 9
Discovery map: 32
- Map of estate of R.O. Longfield in baronies of Athlone & Frenchpark, county Roscommon. 1906 15 A 20 (14-15). ; National Library of Ireland
- Lease of lands of Callow, Co Roscommon, Young & Armstrong to William Longfield, 25 June 1861. D.14316; National Archives of Ireland
Contemporary printed sources
- ''GRIFFITH'S VALUATION OF IRELAND'[Primary Valuation of Tenements]', 1850-1858. : Roscommon Union, 10
- ORDNANCE SURVEY NAME BOOKS, County Roscommon: Vol I, 41
- HUSSEY DE BURGH, U. H. ''The Landowners of Ireland. An alphabetical list of the owners of estates of 500 acres or £500 valuation and upwards in Ireland''. Dublin: Hodges, Foster and Figgis, 1878. [available online at www.askaboutireland.ie] : 278
- PARLIAMENTARY PAPERS. ''Return of owners of land of one acre and upwards, in the several counties .... in Ireland''. HC 1876, LXXX: 317.
- ''GRIFFITH'S VALUATION OF IRELAND'[Primary Valuation of Tenements]', 1850-1858. : Castlerea Union, 109.
- PARLIAMENTARY PAPERS. '' 18th Annual Report of the Congested Districts' Board for Ireland'', [Cd 4927] HC 1909, xvi. Appendix XXXII: 140
- PARLIAMENTARY PAPERS. ''Return of Untenanted Lands in Rural Districts, Distinguishing Demesnes on Which There is a Mansion...'', HC 1906, c, 177: 383 (Rocksavage)